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<title>Debugging with GDB: Analyze Collected Data</title>

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<a name="Analyze-Collected-Data"></a>
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Next: <a href="Tracepoint-Variables.html#Tracepoint-Variables" accesskey="n" rel="next">Tracepoint Variables</a>, Previous: <a href="Set-Tracepoints.html#Set-Tracepoints" accesskey="p" rel="prev">Set Tracepoints</a>, Up: <a href="Tracepoints.html#Tracepoints" accesskey="u" rel="up">Tracepoints</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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<a name="Using-the-Collected-Data"></a>
<h3 class="section">13.2 Using the Collected Data</h3>

<p>After the tracepoint experiment ends, you use <small>GDB</small> commands
for examining the trace data.  The basic idea is that each tracepoint
collects a trace <em>snapshot</em> every time it is hit and another
snapshot every time it single-steps.  All these snapshots are
consecutively numbered from zero and go into a buffer, and you can
examine them later.  The way you examine them is to <em>focus</em> on a
specific trace snapshot.  When the remote stub is focused on a trace
snapshot, it will respond to all <small>GDB</small> requests for memory and
registers by reading from the buffer which belongs to that snapshot,
rather than from <em>real</em> memory or registers of the program being
debugged.  This means that <strong>all</strong> <small>GDB</small> commands
(<code>print</code>, <code>info registers</code>, <code>backtrace</code>, etc.) will
behave as if we were currently debugging the program state as it was
when the tracepoint occurred.  Any requests for data that are not in
the buffer will fail.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top">&bull; <a href="tfind.html#tfind" accesskey="1">tfind</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How to select a trace snapshot
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="tdump.html#tdump" accesskey="2">tdump</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How to display all data for a snapshot
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="save-tracepoints.html#save-tracepoints" accesskey="3">save tracepoints</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">How to save tracepoints for a future run
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